Spectrally Efficient Direct-Detection THz Communication System Enabled by Twin Single-Sideband Modulation and Polarization Division Multiplexing Techniques

We propose a spectrally efficient direct-detection THz communication system based on photonics. The direct detection of polarization division multiplexed (PDM) twin single-sideband (twin-SSB) signals without active polarization control can be realized by adding the optical carrier at the optical receiving side. We verify the feasibility of 5.75 GBd 16QAM PDM twin-SSB signals transmission in 300 GHz direct-detection THz communication system by simulation.